1. Field of the Invention
This invention relates to the fields of pharmacology and pharmacodynamics. More specifically, it concerns the use of cyclodextrins to modify the pharmacodynamic properties of pharmaceutically active agents and vary their iontophoretic transport propertires.
2. Background Information
The present invention involves the iontophoretic transport of pharmaceutically active agents. It has long been recognized that under proper conditions pharmaceutically active agents can pass through the body's epithelial layers and enter the patient's circulation. Representative references to this transdermal mode of administration include the following: U.S. Pat. Nos. 3,598,122 and '123 to Zaffaroni and 4,379,454 to Campbell et al.
It has also been recognized that an electrical current can be used to assist or expedite transdermal delivery. This use of electrical currents to drive materials is called iontophoresis or iontophoretic delivery. Representative references to iontophoresis include the following: "Iontophoresis in Dermatology, a Review" by Joanna B. Sloan et al, Journal of the American Academy of Dermatology (1986) 671; Louis P. Gangarosa et al, The Journal of Pharmacology and Experimental Therapeutics (1980) 212, No. 3, 377, and A. Chantraire et al, Arch. Phys. Med. Rehabil. (January, 1986) 67, 38.
The present invention employs cyclodextrins to facilitate these modes of drug delivery. Three textbooks concerning cyclodextrins are Cyclodextrins and Their Inclusion Complexes by J. Szejtli (Akademiai Kiado, Budapest, 1982); Proceedings of the First International Symposium on Cyclodextrins, edited by J. Szejtli, (D. Reidel Publishing Company, Dordrecht, Holland), and Cyclodextrin Chemistry, by M. L. Bender et al (Springer-Verlag, Berlin, 1978). These three references provide a great deal of information on the preparation and properties of the cyclodextrin materials. In certain preferred embodiments of this invention, ionic cyclodextrins are employed. References directed to ionic cyclodextrins include U.S. Pat. Nos. 3,426,011 and 4,535,152.
Although various elements of the present invention have been disclosed as just described, to applicant's knowledge, the art has not described the use of cyclodextrins to facilitate transdermal drug transport or more specifically to assist in the iontophoretic transport of drugs.